The quasiclassical Green's function for the Dirac equation for an arbitrary localized potential is consistently derived using the Fock—Schwinger proper time method. The method essentially consists of exponentially parametrizing the propagator and disentangling the operator expressions. It allows calculating both the main quasiclassical contribution to and the first quasiclassical correction for the Green's function.

Keywords: proper time method, operator technique, Green's function, quasiclassical approximation PACS: 12.20.−m, 12.20.Ds (all) DOI: 10.3367/UFNe.2017.09.038208 URL: https://ufn.ru/en/articles/2018/9/d/ 000452480000004 2-s2.0-85058469849 2018PhyU...61..896K Citation: Krachkov P A, Mil’shtein A I "An operator derivation of the quasiclassical Green's function" Phys. Usp. 61 896–899 (2018) BibTexBibNote ® (generic)BibNote ® (RIS)MedlineRefWorks Received: 4th, July 2017, accepted: 27th, September 2017 Оригинал: Крачков П А, Мильштейн А И «Вывод квазиклассической функции Грина с помощью операторного метода» УФН 188 992–996 (2018); DOI: 10.3367/UFNr.2017.09.038208